Originally Posted by selluminis
I just redid my system build and realized my EPU switch was in the on position this whole. What could this be doing to voltages? Could it be the reason I am seeming to have way higher voltages than other people with the same OC? I think I set EPU to disabled in the bios. Shouldn't that have taken care of EPU?
(This is the Maxiumus Extreme IV, but it should apply to all motherboards by Asus that have the EPU switch in that series.)
The difference between the EPU switch, BIOS EPU option, and EPU under AiSuite II is as follows:
- EPU Switch: Once enabled, it will enable EPU option in BIOS and default to auto mode.
- BIOS EPU option: There are options to select the level of power saving (lowering Vcore voltage when the loading drops). Both the BIOS option and EPU switch will no effect the performance. However, the stability of high level power saving depending on the quality of the CPU and DRAM.
- EPU under AiSuite II: There are 3 modes to choose from: AUTO (dynamic change multiplier and Vcore based on CPU load), High Performance (EPU OFF), and Max power saving (Drop CPU multiplier to lowest multiplier with the relative VID).
You can benefit from the combined result of the BIOS option and AiSuite II software. If AiSuite II is not installed, it will work as AUTO mode.
So it's my understanding that the EPU switch on the motherboard controls the motherboard components such as VRM, and that by enabling it, it enables it in the BIOS and sets the BIOS to automatic mode. If you were then to disable it in the BIOS, it should actually disable it overall and the switch becomes meaningless.
I also don't recommend using AiSuite II at all; I simply kept it in the quote for posterity's sake.